An image forming apparatus has been known which includes a photosensitive member, on which an electrostatic latent image is to be formed, and a developing roller arranged to be spaced from the photosensitive member and is configured to lower a developing bias when a non-image area of the photosensitive member passes through a developing unit, i.e., during non-developing. An example of such image forming apparatus is disclosed in JP-A-2001-166573.